冻融环境下钢管混凝土带缝剪力墙的抗震性能试验研究

Experimental study on seismic behavior of concrete filled steel tubular slotted shear walls under freeze-thaw environment

针对冻融环境下钢管混凝土的带缝剪力墙抗震性能试验进行研究,通过对在相同的冻融环境下反复经历多次的混凝土带缝剪力墙的整体状态和受破坏程度进行比较分析,从而得出在经过115次的冻融环境下反复操作,冻融在弹性阶段对试件抗震性能影响较小,在进入弹塑性阶段后,试件刚度开始下降,骨架曲线开始弯曲;在极限荷载达到后,试件骨架曲线下降,试件刚度退化明显。方钢管混凝土边框带缝剪力墙延性系数平均值为3.53,方钢管混凝土边框底部加厚带缝剪力墙的延性系数平均值为4.07。在冻融循环次数不相同的时候,可以发现冻融环境反复的次数与我们试件的各项荷载指标呈现着负相关关系,即循环的次数越多,时间的极限荷载和开裂荷载的参数值在不断的减少,极限荷载降低幅度要比开裂荷载的大,并建立了冻融循环次数的墙体受剪承载力公式。

It is mainly to study the seismic performance test of shear wall with slit of concrete filled steel tube under freeze-thaw environment.By comparing the shape and failure process of wall under different freezing and thawing cycles,it is found that after 115 freezing and thawing cycles,the initial cracks of D3 and DZ3 are appeared in advance,and the development of the cracks is more rapid.Speed and D3 and DZ3 have more serious damage than unfrozen samples.After the elastoplastic stage,the stiffness of the specimen begins to decline and the skeleton curve begins to bend.After the ultimate load is reached,the skeleton curve of the specimen is reduced and the stiffness degradation of the specimen is obvious.The average value of the ductility coefficient of the shear walls with square steel tube reinforced concrete side frames is 3.53,and the average value of the ductility coefficient of the shear wall with the thick seam at the bottom of the square concrete-filled steel tube frame is 4.07.When the number of freezing and thawing cycles is different,with the increase of the number of freeze-thaw cycles,the ultimate load and cracking load of the specimen are reduced,the limit load is lower than the cracking load,and the formula of the shear capacity of the wall is established.